Signal processing circuit and signal processing method

Abstract

The present disclosure relates to a signal processing circuit and a signal processing method. The signal processing circuit (100) comprises: a sensor interface (10); a sensor type identification module (20) connected to the sensor interface (10) and comprising at least a first comparator (22) having a first threshold value and a second comparator (24) having a second threshold value different from the first threshold value, wherein a signal (V1) from the sensor interface (10) is input to the first comparator (22) and the second comparator (24) respectively; a signal modulation module (30) configured to modulate the signal from the sensor interface (10); and a processor (40) comprising a first input port connected to the output of the first comparator (22) and a second input port connected to the output of the second comparator (24), wherein the processor (40) is configured to identify the type of the sensor based on the output (V2) of the first comparator (22) and the output (V3) of the second comparator (24).

Description

Technical Field

[0001] The present disclosure relates to the field of signal acquisition, and more particularly to a signal processing circuit and a signal processing method having a sensor type identification function. Background Art

[0002] In the field of signal acquisition, by acquiring the signal from the sensor, the status of the equipment can be effectively detected and corresponding measures can be taken to ensure the reliability and efficiency of the equipment. The signal acquisition system usually needs to collect signals from multiple different types of sensors. Different types of sensors require different processing circuits, which poses a great challenge to the design of the signal processing system. Traditional signal acquisition systems are not satisfactory in supporting the acquisition of multiple types of sensor signals. Summary of the invention

[0003] The purpose of the present disclosure is to provide a signal processing circuit and a signal processing method, aiming to solve one or more of the above problems and other potential problems.

[0004] One aspect of the present disclosure provides a signal processing circuit. The signal processing circuit includes: a sensor interface configured to receive a signal from a sensor; a sensor type identification module connected to the sensor interface and at least including a first comparator having a first threshold and a second comparator having a second threshold different from the first threshold, and the signal from the sensor interface is input to the first comparator and the second comparator respectively; a signal modulation module configured to modulate the signal from the sensor interface; a processor including a first input port connected to the output of the first comparator and a second input port connected to the output of the second comparator, and the processor is configured to identify the type of the sensor based on the output of the first comparator and the output of the second comparator.

[0005] In some embodiments, the signal processing circuit further includes: a first switch, which is arranged in series between the sensor type identification module and the sensor interface; and a second switch, which is arranged in series between the signal modulation module and the sensor interface, wherein the processor includes a sensor type identification mode and a sensor signal processing mode, in which the first switch is closed and the second switch is opened, and the processor is configured to identify the type of the sensor based on the output of the first comparator and the output of the second comparator; in the sensor signal processing mode, the first switch is opened and the second switch is closed.

[0006] In some embodiments, the signal processing circuit further includes an integral amplifier circuit, wherein in the sensor type identification mode, the integral amplifier circuit is implemented as a part of the sensor type identification module, and the signal from the sensor interface is integrated and processed by the integral amplifier circuit and then input into the first comparator and the second comparator respectively; in the sensor signal processing mode, the integral amplifier circuit is selectively implemented as a part of the signal modulation module according to the identified type of the sensor.

[0007] In some embodiments, the signal processing circuit further includes: a third switch, which is arranged in series between a comparator module including the first comparator and the second comparator and the integral amplifier circuit; and a fourth switch, which is arranged in series between the integral amplifier circuit and a first node, and the signal modulation module is connected to the second switch at the first node; wherein in the sensor type identification mode, the third switch is closed and the fourth switch is opened, and in the sensor signal processing mode, the third switch is opened and the fourth switch is selectively closed or opened based on the determined sensor type.

[0008] In some embodiments, in the sensor signal processing mode, the processor includes a first sensor mode and a second sensor mode, and the processor is configured to: in response to determining that the sensor is a first sensor type, command the fourth switch to close so that the signal from the sensor interface is sent to the signal modulation module after being processed by the integral amplifier circuit; and in response to determining that the sensor is a second sensor type, command the fourth switch to open.

[0009] In some embodiments, the first sensor type includes a charge-type sensor; and / or the second sensor type includes one or more of an eddy current displacement sensor and an integrated circuit-type piezoelectric sensor.

[0010] In some embodiments, the signal modulation module includes an adjustable gain amplification circuit, and the processor is configured to adjust the gain of the adjustable gain amplification circuit based on the magnitude of the signal modulated by the signal modulation module.

[0011] In some embodiments, the signal processing circuit also includes a power module, which includes: a programmable constant current source; a voltage branch, connected in parallel with the constant current source and including a fifth switch and a ground resistor connected in series with each other; and a sixth switch, which is arranged in series between the sensor type identification module and the second node, and the voltage branch is connected to the constant current source at the second node; wherein the processor also includes a first fault detection mode, in which the fifth switch and the sixth switch are closed, and the processor is configured to: obtain the output of the first comparator and the output of the second comparator, and compare the output of the first comparator and the output of the second comparator with the first mode signal output by the constant current source, and determine whether the sensor type identification module is normal based on the comparison.

[0012] In some embodiments, the signal processing circuit also includes a seventh switch, which is arranged in series between the second node and the second switch, wherein the processor also includes a second fault detection mode, in which the first switch is opened, the second switch is closed, and the fifth switch and the seventh switch are closed, and the processor is configured to: obtain the output of the signal modulation module, and compare the output of the signal modulation module with the second mode signal output by the constant current source, and determine whether the signal modulation module is normal based on the comparison.

[0013] In some embodiments, the processor also includes a third fault detection mode. In the third fault detection mode, the first switch is closed, the seventh switch is open, the third switch is open, and the fourth switch is closed. The processor is configured to: obtain the output of the signal modulation module, and compare the output of the signal modulation module with the third mode signal output by the constant current source, and determine whether the integral amplifier circuit is normal based on the comparison.

[0014] In some embodiments, the signal processing circuit also includes an eighth switch arranged between the constant current source and the second node and a ninth switch arranged between the constant current source and the sensor interface, wherein when the processor is in a fault detection mode, the eighth switch is closed and the ninth switch is open; the processor also includes a sensor power supply mode, in which the processor is configured to close the ninth switch in response to determining that the sensor needs power so as to supply power to the sensor via the constant current source.

[0015] Another aspect of the present disclosure provides a signal processing method. The signal processing method includes: acquiring a sensor signal from a sensor interface; inputting the sensor signal to a sensor type identification module, the sensor type identification module including a first comparator having a first threshold and a second comparator having a second threshold different from the first threshold; and identifying the type of the sensor based on an output of the first comparator and an output of the second comparator.

[0016] In some embodiments, the signal processing method further includes: based on the determined type of the sensor, selecting a sensor modulation circuit corresponding to the type of the sensor from a plurality of sensor modulation circuits.

[0017] In some embodiments, the signal processing method also includes: providing a fault detection signal to at least one of the sensor type identification module and the signal modulation module by a programmable constant current source; obtaining a response signal to the fault detection signal by at least one of the sensor type identification module and the signal modulation module; determining whether at least one of the sensor type identification module and the signal modulation module is normal based on the response signal; and executing the step of obtaining a sensor signal from the sensor interface in response to determining that at least one of the sensor type identification module and the signal modulation module is normal.

[0018] The signal processing circuit and method according to the present invention can achieve one or more of the following technical effects: it can automatically support signal acquisition of various types of sensors without the need for multiple modules to perform signal conditioning separately, thereby simplifying the complexity of the system; it can realize automatic identification of sensor types; it does not need to manually perform complicated channel settings, and the modulation circuit can be adaptively selected according to the sensor type identified by the sensor type; it can support automatic channel fault diagnosis of the system; it can support automatic range setting, and can automatically adjust the adjustable gain differential amplifier circuit according to the size of the external sensor signal, so as to make the resolution and acquisition accuracy higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the embodiments of the present disclosure will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown by way of example and not limitation.

[0020] Figure 1 An overall schematic diagram of a signal processing system according to an embodiment of the present disclosure is shown.

[0021] Figure 2 A circuit implementation schematic diagram of a signal processing circuit according to an embodiment of the present disclosure is shown.

[0022] Figure 3A schematic diagram of a circuit implementation of a signal processing circuit in a sensor type identification mode according to an embodiment of the present disclosure is shown.

[0023] Figure 4 A first circuit implementation schematic diagram of a signal processing circuit in a sensor signal processing mode according to the present disclosure is shown.

[0024] Figure 5 A second circuit implementation schematic diagram of the signal processing circuit according to the present disclosure in a sensor signal processing mode is shown.

[0025] Figure 6 A circuit implementation schematic diagram of a signal processing circuit in a first fault detection mode according to the present disclosure is shown.

[0026] Figure 7 A circuit implementation schematic diagram of a signal processing circuit in a second fault detection mode according to the present disclosure is shown.

[0027] Figure 8 A circuit implementation schematic diagram of a signal processing circuit in a third fault detection mode according to the present disclosure is shown. DETAILED DESCRIPTION

[0028] Unless otherwise indicated, corresponding numbers and symbols in different figures generally refer to corresponding regions. The accompanying drawings are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale. The edges of features drawn in the drawings do not necessarily represent the end of the feature range.

[0029] References to "one embodiment" or "an implementation" in the framework of this specification are intended to indicate that a particular configuration, structure, or characteristic described with respect to the embodiment is included in at least one embodiment. Therefore, phrases such as "in an embodiment," "in one embodiment," etc., which may appear in various aspects of this specification, do not necessarily refer to exactly the same embodiment. Furthermore, particular configurations, structures, or characteristics may be combined in any appropriate manner in one or more embodiments.

[0030] According to the present disclosure, a signal processing circuit and a signal processing method are provided, which support the identification of multiple different types of sensors and automatically set corresponding signal modulation circuits based on the identification results of the sensors. The signal processing system according to the embodiment of the present disclosure is described in detail below with reference to the accompanying drawings.

[0031] Figure 1 FIG. 1 shows an overall schematic diagram of a signal processing system according to an embodiment of the present disclosure. Figure 1As shown, the signal processing circuit system may include a signal processing circuit 100 and one or more sensors 20. The signal processing circuit 100 is configured to collect signals from the plurality of sensors 200 and process the collected signals to determine the state of the device. Figure 1 As shown, the signal processing circuit 100 includes a sensor interface 10 , a sensor type identification module 20 , a signal modulation module 30 and one or more processors 40 .

[0032] The sensor interface 10 is configured to receive signals from a plurality of sensors 200. The sensors 200 may be sensors of different types. Taking vibration measurement as an example, the sensor may be an integrated circuit piezoelectric (IEPE) sensor, a charge sensor, an eddy current displacement sensor, etc. It should be understood that the sensor may be other forms of motion besides vibration.

[0033] The sensor type identification module 20 is connected to the sensor interface 10 and includes a comparator module, which includes a first comparator 22 having a first threshold and a second comparator 24 having a second threshold different from the first threshold. As an example, the comparators 22 and 24 can be voltage comparators with different voltage thresholds. The signal from the sensor interface 10 is input to the first comparator 22 and the second comparator 24, respectively, and the processor 40 can receive the output signals from the first comparator 22 and the second comparator 24 and identify the type of the sensor. The signal modulation module 30 is configured to modulate the signal from the sensor interface 10. The signal modulation module 30 may include different modulation circuits for different types of sensors.

[0034] The signal processing circuit 100 further includes a first switch K1 and a second switch K2. The first switch K1 is arranged in series between the sensor type identification module 20 and the sensor interface 10, and can be controlled, for example, by the processor 40, to be opened or closed. The second switch K2 is arranged in series between the signal modulation module 30 and the sensor interface 10, and can be controlled, for example, by the processor 40, to be opened or closed.

[0035] The processor 40 includes a sensor type identification mode and a sensor signal processing mode. The processor can switch between different modes through the first switch and the second switch. In the sensor type identification mode, the first switch K1 is closed and the second switch K2 is open, and the signal from the sensor interface 10 can be input to the sensor type identification module 20. The processor 40 can identify the type of the sensor based on the output V2 of the first comparator 22 and the output V3 of the second comparator 24 (see later). Figure 3Detailed description). In the sensor signal processing mode, the first switch K1 is opened and the second switch K2 is closed, and the signal from the sensor interface 10 can be input to the signal modulation module 30, and after being modulated by the signal modulation module 30, the sensor signal can be collected (refer to Figure 4 Detailed description).

[0036] Figure 2 A circuit implementation schematic diagram of a signal processing circuit according to an embodiment of the present disclosure is shown. The signal processing circuit 100 includes a sensor interface 10, a sensor type identification module 20, a signal modulation module 30, and one or more processors 40. The processor 40 is exemplified as a microprocessor MCU, and it should be understood that the processor 40 can be implemented as a computing device with input and output ports such as an FPGA or DSP. The signal modulation module 30 may include a signal modulation circuit, such as a voltage follower 32, a bandpass filter 34, and an adjustable gain amplifier circuit 36. It should be understood that these components are merely exemplary, and the signal modulation circuit may include other circuit components, for example, other types of filters may be substituted for the bandpass filter 34, and in some cases, the voltage follower 32 may be omitted.

[0037] In some embodiments, Figure 2 As shown, the signal processing circuit 100 may further include an integral amplifier circuit 60. The integral amplifier circuit 60 is also called a charge amplifier circuit, which can amplify an external charge signal into a voltage signal. This is particularly suitable for a charge type sensor. When a charge type sensor is not included in the multiple sensor types, the integral amplifier circuit 60 can be omitted.

[0038] In some embodiments, Figure 2 As shown, the signal processing circuit 100 may further include a third switch K3 and a fourth switch K4. The third switch K3 is arranged in series between the integral amplifier circuit 60 and the comparator module. The fourth switch K4 is arranged in series between the integral amplifier circuit 60 and the first node Q, and the second switch K2 is connected to the signal modulation module 30 at the first node Q. The third switch K3 and the fourth switch K4 may be controlled by the processor 40, for example, to be opened or closed. In some embodiments, in the sensor type recognition mode, the third switch K3 is closed and the fourth switch K4 is opened; in the sensor signal processing mode, the third switch K3 is opened and the fourth switch K4 is selectively closed or opened based on the determined sensor type.

[0039] In some embodiments, the integral amplifier circuit 60 can be implemented as a part of the sensor type identification module 20 by switching the states of the switches K3 and K4, and the signal from the sensor interface 10 is integrated and processed by the integral amplifier circuit 60 and then respectively input to the first comparator 22 and the second comparator 24. In some embodiments, according to the type of the identified sensor, the integral amplifier circuit 60 can be selectively implemented as a part of the signal modulation module 30 by switching the states of the switches K3 and K4, and the signal from the sensor interface 10 is integrated and processed by the integral amplifier circuit 60 and then respectively input to other components of the signal modulation module 30. In some embodiments, if the type of the identified sensor is, for example, a charge type sensor, the integral amplifier circuit 60 is implemented as a part of the signal modulation module 30. If the type of the identified sensor is not a charge type sensor, the integral amplifier circuit 60 is not implemented as a part of the signal modulation module 30.

[0040] In some embodiments, Figure 2 As shown, the signal processing circuit 100 may further include a power module 50, which may provide additional functions for the signal processing circuit 100. In some embodiments, the power module 50 may provide signals for function detection of various modules of the signal processing circuit 100. In some embodiments, the power module 50 may also be used to power the sensor interface 20, which may be required in some sensors (e.g., IEPE sensors).

[0041] In some embodiments, Figure 2 As shown, the power module 50 includes a constant current source 52 and a voltage branch for providing a voltage. The voltage branch can be connected in parallel with the constant current source 52 and includes a fifth switch K5 and a ground resistor 54 connected in series with each other. According to the present disclosure, the constant current source 52 is a programmable constant current source, which significantly enhances the function of the constant current source (which will be referred to later). Figure 6-Figure 8 Further explanation). The constant current source may be controlled by programming of the processor 40. The fifth switch K5 may be controlled, for example, by the control of the processor 40 to open the voltage branch or close the voltage branch.

[0042] In some embodiments, Figure 2 As shown, the signal processing circuit 100 may further include a sixth switch K6 and a seventh switch K7. The sixth switch K6 is arranged in series between the sensor type identification module 20 and the node P. The seventh switch K7 is arranged in series between the node P and the second switch K2. The sixth switch K6 and the seventh switch K7 may be controlled by the processor 40 to implement different functions of the signal processing circuit. In some embodiments, as Figure 2 As shown, the first switch K1 and the seventh switch K7 can be implemented in a single switch with two switching positions.

[0043] In some embodiments, Figure 2 As shown, the signal processing circuit 100 may further include an eighth switch K8 and a ninth switch K9. The eighth switch K8 may be disposed between the constant current source 52 and the node P. The ninth switch K9 may be disposed between the constant current source 52 and the sensor interface 10. The eighth switch K8 and the ninth switch K9 may be controlled by the processor 40 to implement different functions of the signal processing circuit. In some embodiments, as Figure 2 As shown, the eighth switch K8 and the ninth switch K9 can be implemented in a single switch with two switching positions.

[0044] Figure 3 FIG. 2 shows a schematic diagram of a circuit implementation of a signal processing circuit in a sensor type identification mode according to an embodiment of the present disclosure. Figure 3 As shown, in the sensor type identification mode, the first switch K1 is closed, the third switch K3 is closed, and the fourth switch K4 is open. The signal V1 from the sensor interface 10 can sequentially pass through the first switch K1, the integral amplifier circuit 60, and the third switch K3 to reach the comparator module, and is processed by the high voltage comparator 22 and the low voltage comparator 22 to output signals V2 and V3 respectively. The processor 40 can determine the type of the sensor based on the V2 and V3 signals.

[0045] The following is explained using three types of sensors as examples. In some embodiments, when the connected sensor is an eddy current displacement sensor, since the output of the eddy current displacement sensor is a negative level, by integrating and amplifying the negative level, it will be integrated into the minimum negative voltage. When the connected sensor is a charge type sensor, since the charge type sensor has an output charge amount close to 0 coulomb when it is not subjected to external vibration, by integrating and amplifying it, the amplified voltage signal is also a smaller voltage signal with an amplitude close to 0V. When the connected sensor is an IEPE type sensor, a constant current source needs to be connected to power it. Since the voltage signal output by the IEPE type sensor has a positive voltage bias when it is not subjected to external vibration, by integrating and amplifying it, the amplified voltage signal is the maximum positive voltage. According to the analysis, it can be summarized as the following truth table 1, as follows:

[0046] Table 1 Sensor type truth table

[0047]

[0048] The sensor type identification process is as follows: first, the sensor is connected, and no constant current source is used to power it. After amplification by the integral amplifier circuit, the voltage is compared with the high voltage threshold and the low voltage threshold at the comparator. When the voltage of V2 and V3 identified by the MCU is 0, it can be confirmed as an eddy current displacement sensor. It is also necessary to distinguish between charge type sensors and IEPE type sensors. When the voltage of V2 and V3 identified by the MCU is 1, the connected sensor is an IEPE type sensor, otherwise it is an eddy current displacement sensor. In some embodiments, for IEPE type sensors, K9 can be closed and powered by a constant current source. Two comparators are used in the illustrated embodiment, and it should be understood that this is merely exemplary, and a larger number of comparators can be used depending on the type of sensor.

[0049] In some embodiments, processor 40 may set different sensor modes depending on the identified sensor type. Figure 4 and Figure 5 The first circuit implementation schematic diagram and the second circuit implementation schematic diagram of the signal processing circuit according to the present disclosure in the sensor signal processing mode are respectively shown. It should be understood that the illustrated embodiments are only exemplary. The signal processing circuit can have more than two sensor modes depending on the type of sensor.

[0050] exist Figure 4 In the first sensor mode shown, the first switch K1 is closed, the seventh switch K7 is open, and the fourth switch K4 is closed, and the signal V1 from the sensor interface 10 is modulated and input into the processor 40 . Figure 4 The circuit shown is particularly suitable for charge-type sensors, which can integrate and amplify sensor signals, perform voltage buffering, signal filtering, and amplitude adaptive adjustment, and finally input the signals into a processor. Figure 4 As shown, the signal V1 from the sensor interface 10 is amplified by the integral amplifier circuit 60 and sent to the signal modulation module 30. At the signal modulation module, it is processed into a signal V4 after passing through the voltage follower 32, the bandpass filter 34, and the adjustable gain amplifier circuit 36 ​​in sequence, and then input into the processor 40 after passing through the AD converter 70.

[0051] exist Figure 5 In the second sensor mode shown, the first switch K1 is open, the seventh switch K7 is closed, the second switch is closed, and the fourth switch K4 is open. Figure 4 Compared with the modulation circuit, Figure 5 In the embodiment shown, the signal V1 from the sensor interface 10 is directly sent to the signal modulation module 30 without being amplified by the integral amplifier circuit 60. This is particularly suitable for IEPE type sensors and eddy current displacement sensors.

[0052] In some embodiments, in order to achieve higher precision signal measurement, the processor 40 can adaptively adjust the amplification factor of the adjustable gain amplifier circuit 36 ​​by sampling the signal value in real time and switching different switches. In some embodiments, as an example, the system can preset 4 ranges, namely X1, X5, X10 and X20. For example, the full scale is 10V at this time, and the signal is 0.4V at this time. When the X1 gear is selected, the 10V gear is used to measure it, the resolution is low, and the sampling accuracy is low; the processor 40 can switch to the X20 gear for amplification, and the resolution and sampling accuracy can be correspondingly improved. Through this process, the amplification factor can be adaptively adjusted.

[0053] In some embodiments, before the signal processing circuit 100 identifies the sensor type, it can also perform fault detection on each functional module of the signal processing circuit 100 to confirm whether each functional module is working properly. If each functional module is working properly, the sensor is connected, otherwise a warning is issued through the processor. According to the present disclosure, fault detection of each functional module of the signal processing circuit 100 can be achieved through the programmable power supply module 50 and the switching of each switch.

[0054] Figure 6 FIG. 2 shows a schematic diagram of a circuit implementation of a signal processing circuit according to the present disclosure in a first fault detection mode. The first fault detection mode corresponds to the fault detection of the sensor type identification circuit 20. Figure 6 As shown, in the first fault detection mode, the sixth switch K6 is closed, and the fifth switch K5 and the eighth switch K8 are closed, thereby forming a path from the power supply module 50 to the processor 40 via the sensor type identification module 20. In the first fault detection mode, the constant current source 52 outputs a first mode signal. The first mode signal from the constant current source 52 is processed by the first comparator 22 and the second comparator 24 and output to the processor 40. The processor 40 obtains the output V2 of the first comparator 22 and the output V3 of the second comparator 24, and compares the output of the first comparator 22 and the output of the second comparator 24 with the first mode signal output by the constant current source 52, and determines whether the sensor type identification module 20 is normal based on the comparison. As an example, the constant current source 52 outputs a 100Hz square wave current signal, and the square wave current signal is converted into a 100Hz square wave voltage signal through the ground resistor 54. After passing through the DC blocking capacitor C1, when the sensor type identification circuit 20 operates normally, it is converted into different square wave signals V2 and V3 through the first comparator 22 and the second comparator 24. If the processor cannot detect a different square wave signal, it indicates that the sensor type identification circuit 20 is abnormal.

[0055] Figure 7The circuit implementation schematic diagram of the signal processing circuit in the second fault detection mode according to the present disclosure is shown. The second fault detection mode corresponds to the fault detection of the signal modulation module 30. As shown in Figure 7, in the second fault detection mode, the seventh switch K7 is closed, the second switch K2 is closed, and the fifth switch K5 and the eighth switch K8 are closed, thereby forming a path from the power supply module 50 to the processor 40 via the signal modulation module 30. The constant current source 52 outputs a second mode signal. The second mode signal from the constant current source 52 is processed by each functional module of the signal modulation module 30 and output to the processor 40. The processor 40 obtains the output V4 of the signal modulation module 30, and compares it with the second mode signal output by the constant current source 52, and determines whether the signal modulation module 30 is normal based on the comparison. As an example, the constant current source 52 outputs a DC signal with a positive amplitude, which passes through the voltage follower 32, the bandpass filter 34 and the adjustable gain amplifier circuit 36 ​​of the signal modulation module 3, and finally passes through the AD converter 70 to the processor 40. The processor 40 can determine whether the signal modulation module 30 is normal based on comparing the collected signal with the amplitude of the DC signal.

[0056] Figure 8 FIG7 shows a schematic diagram of a circuit implementation of a signal processing circuit according to the present disclosure in a third fault detection mode. The third fault detection mode corresponds to the fault detection of the integral amplifier circuit 60. As shown in FIG7, in the third fault detection mode, the first switch K1 is closed, the fourth switch K4 is closed, and the fifth switch K5 and the eighth switch K8 are closed, thereby forming a path from the power supply module 50 to the processor 40 via the integral amplifier circuit 60 and the signal modulation module 30. The constant current source 52 outputs a third mode signal. The third mode signal from the constant current source 52 is processed by the integral amplifier circuit 60 and each functional module of the signal modulation module 30 and is output to the processor 40. The processor 40 obtains the output V4 of the signal modulation module 30, and compares it with the third mode signal output by the constant current source 52, and determines whether the signal integral amplifier circuit 60 is normal based on the comparison. As an example, the constant current source 52 outputs a 100 Hz sine wave signal, which is amplified by the integral amplifier circuit 60 and processed by the voltage follower 32, the bandpass filter 34 and the adjustable gain amplifier circuit 36 ​​of the signal modulation module 3, and finally reaches the processor 40 via the AD converter 70. The processor 40 can determine whether the integral amplifier circuit 60 is normal based on the comparison of the collected signal with the input signal.

[0057] It should be understood that the fault detection mode of the illustrated embodiment is merely exemplary. In some embodiments, in order to detect whether the integral amplifier circuit 60 is normal, instead of connecting the integral amplifier circuit 60 to the signal modulation module 30, the integral amplifier circuit 60 can be connected to the sensor type identification module, and the detection can also be achieved.

[0058] According to the present disclosure, a signal processing method is also provided. In some embodiments, after the signal processing circuit is powered on, the programmable constant current source and each switch can be controlled to perform fault diagnosis on each functional module of the signal processing circuit, and after determining that each functional module operates normally, the sensor signal acquisition is performed, otherwise the processor can alarm according to the fault condition.

[0059] In some embodiments, during fault detection, a programmable constant current source 52 provides a fault detection signal to at least one of the sensor type identification module 20 and the signal modulation module 30; a response signal to the fault detection signal from at least one of the sensor type identification module 20 and the signal modulation module 30 is obtained; based on the response signal, it is determined whether at least one of the sensor type identification module 20 and the signal modulation module 30 is normal; and in response to determining that at least one of the sensor type identification module 20 and the signal modulation module 30 is normal, a step of obtaining a sensor signal from the sensor interface 10 is performed.

[0060] In some embodiments, during signal acquisition, a sensor signal is obtained from a sensor interface 10; the sensor signal is input into a sensor type identification module 20, the sensor type identification module 20 includes a first comparator 22 having a first threshold and a second comparator 24 having a second threshold different from the first threshold; the type of the sensor is identified based on the output of the first comparator 22 and the output of the second comparator 24.

[0061] In some embodiments, based on the determined type of the sensor, a sensor modulation circuit corresponding to the type of the sensor is selected from a plurality of sensor modulation circuits.

[0062] In some embodiments, the gain of the adjustable gain amplifier circuit is adjusted based on the size of the collected signal.

[0063] The signal processing circuit and method according to the present invention can achieve one or more of the following technical effects: it can automatically support signal acquisition of various types of sensors without the need for multiple modules to perform signal conditioning separately, thereby simplifying the complexity of the system; it can realize automatic identification of sensor types; it does not need to manually perform complicated channel settings, and the modulation circuit can be adaptively selected according to the sensor type identified by the sensor type; it can support automatic channel fault diagnosis of the system; it can support automatic range setting, and can automatically adjust the adjustable gain differential amplifier circuit according to the size of the external sensor signal, so as to make the resolution and acquisition accuracy higher.

[0064] Through the teachings given in the above description and the related drawings, many modifications and other embodiments of the present disclosure given here will be recognized by those skilled in the art of the present disclosure. Therefore, it is to be understood that the embodiments of the present disclosure are not limited to the specific embodiments disclosed, and modifications and other embodiments are intended to be included in the scope of the present disclosure. In addition, although the above description and the related drawings describe the example embodiments in the context of some example combinations of parts and / or functions, it should be appreciated that different combinations of parts and / or functions can be provided by alternative embodiments without departing from the scope of the present disclosure. In this regard, for example, other combinations of parts and / or functions that are different from those clearly described above are also expected to be within the scope of the present disclosure. Although specific terms are used here, they are only used in a general and descriptive sense and are not intended to be limited.

Claims

1. A signal processing circuit (100), comprising: A sensor interface (10) configured to receive a signal from a sensor (200); a sensor type identification module (20) connected to the sensor interface (10) and comprising at least a first comparator (22) having a first threshold value and a second comparator (24) having a second threshold value different from the first threshold value, wherein a signal (V1) from the sensor interface (10) is input to the first comparator (22) and the second comparator (24), respectively; A signal modulation module (30) configured to modulate the signal from the sensor interface (10); A processor (40) comprising a first input port connected to the output of the first comparator (22) and a second input port connected to the output of the second comparator (24), the processor (40) being configured to identify the type of the sensor based on the output (V2) of the first comparator (22) and the output (V3) of the second comparator (24); The signal processing circuit further comprises: A first switch (K1) is arranged in series between the sensor type identification module (20) and the sensor interface (10); as well as A second switch (K2) is arranged in series between the signal modulation module (30) and the sensor interface (10), The processor (40) includes a sensor type identification mode and a sensor signal processing mode. In the sensor type identification mode, the first switch (K1) is closed and the second switch (K2) is open, and the processor (40) is configured to identify the type of the sensor based on the output (V2) of the first comparator (22) and the output (V3) of the second comparator (24); in the sensor signal processing mode, the first switch (K1) is open and the second switch (K2) is closed.

2. The signal processing circuit according to claim 1, further comprising an integral amplifier circuit (60), wherein in the sensor type identification mode, the integral amplifier circuit (60) is implemented as a part of the sensor type identification module (20), and the signal from the sensor interface (10) is integrated and processed by the integral amplifier circuit (60) and then input into the first comparator (22) and the second comparator (24) respectively; in the sensor signal processing mode, the integral amplifier circuit (60) is selectively implemented as a part of the signal modulation module (30) according to the identified type of the sensor.

3. The signal processing circuit according to claim 2, further comprising: A third switch (K3) is arranged in series between a comparator module including the first comparator and the second comparator and the integral amplifier circuit (60); as well as a fourth switch (K4) arranged in series between the integral amplifier circuit (60) and the first node (Q), and the signal modulation module (30) is connected to the second switch at the first node (Q); Wherein in the sensor type identification mode, the third switch (K3) is closed and the fourth switch (K4) is open, In the sensor signal processing mode, the third switch (K3) is open and the fourth switch (K4) is selectively closed or opened based on the determined sensor type.

4. The signal processing circuit according to claim 3, wherein In the sensor signal processing mode, the processor (40) includes a first sensor mode and a second sensor mode. The processor (40) is configured to: in response to determining that the sensor is a first sensor type, command the fourth switch (K4) to close, so that the signal from the sensor interface (10) is sent to the signal modulation module (30) after being processed by the integral amplifier circuit (60); and in response to determining that the sensor is a second sensor type, command the fourth switch (K4) to open.

5. The signal processing circuit according to claim 4, wherein the first sensor type comprises a charge type sensor; and / or the second sensor type comprises one or more of an eddy current displacement sensor and an integrated circuit type piezoelectric sensor.

6. The signal processing circuit according to claim 1, wherein the signal modulation module (30) comprises an adjustable gain amplification circuit, and the processor (40) is configured to adjust the gain of the adjustable gain amplification circuit based on the size (V4) of the signal modulated by the signal modulation module (30).

7. The signal processing circuit according to claim 3, further comprising a power supply module, wherein the power supply module comprises: Programmable constant current source (52); a voltage branch connected in parallel with the constant current source (52) and comprising a fifth switch (K5) and a ground resistor (54) connected in series with each other; and a sixth switch (K6) arranged in series between the sensor type identification module (20) and a second node (P), the voltage branch being connected to the constant current source (52) at the second node (P); The processor (40) further includes a first fault detection mode. In the first fault detection mode, the fifth switch (K5) and the sixth switch (K6) are closed, and the processor (40) is configured to: obtain the output of the first comparator (22) and the output of the second comparator (24), and compare the output of the first comparator (22) and the output of the second comparator (24) with the first mode signal output by the constant current source (52), and determine whether the sensor type identification module (20) is normal based on the comparison.

8. The signal processing circuit according to claim 7, further comprising a seventh switch (K7) arranged in series between the second node (P) and the second switch (K2), The processor (40) further includes a second fault detection mode. In the second fault detection mode, the first switch (K1) is opened, the second switch (K2) is closed, the fifth switch (K5) and the seventh switch (K7) are closed, and the processor (40) is configured to: obtain the output of the signal modulation module (30), compare the output of the signal modulation module (30) with the second mode signal output by the constant current source (52), and determine whether the signal modulation module (30) is normal based on the comparison.

9. The signal processing circuit according to claim 8, wherein the processor (40) further comprises a third fault detection mode, in which the first switch (K1) is closed, the seventh switch (K7) is opened, the third switch (K3) is opened, and the fourth switch (K4) is closed. The processor (40) is configured to: obtain the output of the signal modulation module (30), compare the output of the signal modulation module (30) with the third mode signal output by the constant current source (52), and determine whether the integral amplifier circuit (60) is normal based on the comparison.

10. The signal processing circuit according to any one of claims 7 to 9, further comprising an eighth switch (K8) arranged between the constant current source (52) and the second node (P) and a ninth switch (K9) arranged between the constant current source (52) and the sensor interface (10), wherein when the processor (40) is in a fault detection mode, the eighth switch (K8) is closed and the ninth switch (K9) is opened; The processor (40) further includes a sensor power supply mode, in which the processor (40) is configured to close the ninth switch (K9) in response to determining that the sensor needs power supply, so as to supply power to the sensor via the constant current source (52).

11. A signal processing method, comprising: Acquiring a sensor signal from a sensor interface (10); Inputting the sensor signal into a sensor type identification module (20), wherein the sensor type identification module (20) includes a first comparator (22) having a first threshold value and a second comparator (24) having a second threshold value different from the first threshold value; as well as identifying the type of the sensor based on the output of the first comparator (22) and the output of the second comparator (24); The method further comprises: Providing a fault detection signal to at least one of a sensor type identification module (20) and a signal modulation module (30) by a programmable constant current source (52); Acquiring a response signal from at least one of the sensor type identification module (20) and the signal modulation module (30) to the fault detection signal; Based on the response signal, determining whether at least one of the sensor type identification module (20) and the signal modulation module (30) is normal; and In response to determining that at least one of the sensor type identification module (20) and the signal modulation module (30) is normal, the step of acquiring a sensor signal from the sensor interface (10) is performed.

12. The signal processing method according to claim 11, further comprising: Based on the determined type of the sensor, a sensor modulation circuit corresponding to the type of the sensor is selected from a plurality of sensor modulation circuits.

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